Bulldogs football manager Graham Lowe said the 202cm ruckman had not been able to meet the standards required by the club.
"After some promising early signs, Luke had difficulties finding his feet in an elite AFL program," Lowe said.
"It was mutually agreed that the level of commitment required to be an AFL player was too difficult for Luke at this stage of his life.
"The club had worked with Luke, his management and family throughout the season to help him consistently meet professional standards, and will continue to provide ongoing support for him from a welfare perspective."